1. Field of the Invention
The invention relates to a device for carrying fluids for a medical treatment device with two balancing chambers of equal volume which are each separated into a first and a second partial chamber by means of a flexible separating wall. Each of the first partial chambers has at least one first supply line and at least one first discharge line, and each of the second partial chambers has at least a second supply line and at least a second discharge line, as well as an analysis device.
2. Description of the Related Art
In order to remove substances usually eliminated with urine, and for the removal of fluids, several different processes are used with acute and chronic kidney failure for the surgical purification of blood, or treatment of blood, respectively. In hemodialysis (HD), diffuse translocation prevails, while convective translocation via a membrane is available in the case of hemofiltration (HF). A combination of both processes results in hemodiafiltration (HDF). In peritoneal dialysis (PD) peritoneum is utilized as the contact membrane.
Due to the large exchange quantities, the necessity of an exact balancing process of the fluids removed from the patient and the fluids recirculated to the patient during the entire treatment period exists with the said process.
A hemodiafiltration device with volumetric balancing is known, for instance, from DE 26 34 238 A1. The balancing device of the known hemodiafiltration device has a volume-rigid hollow body, which is separated into two chambers by means of a flexible separating wall. Each chamber has an input and outlet, on which supply and discharge lines for fresh or used dialyzing fluids are arranged, whereby a shut-off valve is switched in each line. Furthermore, pumps are provided for carrying the fresh and used dialyzing fluid, as well as a control unit, which allow the alternating filling of the two chambers. A pressure gauge device is each arranged in the input line of the first and second chambers, which monitors the pressure in the line. Once a chamber is filled, a pressure increase occurs, which switches the respective pump off.
U.S. Pat. No. 4,431,425 A describes a device for the detection of the position of the flexible separating wall of a balancing device with an optical detector, which is arranged on the exterior of the balancing chamber. The known device is of disadvantage insofar as the housing of the balancing chamber must consist of a transparent material.
A device for carrying fluids for a medical treatment device is known from DE 197 28 800 C1, in which pressure impulses are received per time units in a balancing chamber. In this way, the frequency of balancing chamber strokes can be determined per time unit. This represents the monitoring process of the complete filling and draining of the balancing chamber.
A balancing chamber system is also known from DE 28 38 414 C2, according to which any leak possibly occurring in the membrane-like separating wall of the respective carrying chamber, or the balancing chamber, respectively, can be detected by means of a conductivity monitoring system. Such a leak is undesired, as it leads to the mixing of fresh and used dialyzing fluids, which particularly results in a change in treatment effectiveness.
Additionally, the filling condition of the balancing chamber is difficult to detect, because the pressure increase at the end of the circulation cycle is not very distinct. The leak detection by means of a conductivity monitoring system, however, is not capable of functioning precisely, because the conductivity of the mixed fluids hardly differs from each other. Particularly small leaks can practically not be detected at all.